This is a LEAP YEAR
Monday January 1, 2024 – Tuesday, December 31, 2024. What do you do with an extra day. We could do some Spring cleaning. Yeah! But anyway because the actual length of a year isn’t exactly 365.25 days—it’s a little bit shorter. To account for this, we have a rule: a year is a leap year if it is divisible by 4, but if it is also divisible by 100, it is not a leap year unless it is also divisible by 400. Generally, leap years coincide with presidential election years. However, that has not always held true. Nineteen Hundred was a presidential election year, but not a leap year, as was Eighteen Hundred; but for the most part, leap years have been every four years that we elect a new president.
In a Leap year an extra day gets added to the calendar. Leap day falls on Feb. 29, giving the shortest month of the year one added day. The reason there are leap days, and years, is because of the Earth’s orbit. The amount of days it takes for the Earth to complete a full revolution around the Sun is not a whole number. The 365 days we experience is actually 365.242190 days, according to the National Air and Space Museum. Getting rid of those 0.242190 days adds up. That fraction allows seasons to correctly line up each year. This would impact other aspects of life, such as the growing and harvesting of crops. When added, four 0.242190 days roughly equal one full day, which is why Feb. 29 is added to the calendar of most years that are divisible by four, including 2024.
The concept of adding leap days is not new. Some calendars – such as the Hebrew, Chinese and Buddhist calendars – contained leap months, also known as “intercalary or interstitial months,” according to the History Channel. To make up for decimals of time, we’ll sometimes skip leap years, but it’s rare. Prepare for a little bit of math: years divisible by 100 but not 400 are skipped, meaning we skipped leap years in 1700, 1800 and 1900 but not 2000. The next leap year we’ll skip is quite a ways away, in 2100.
When making the Julian calendar, Caesar took inspiration from the Egyptians and decided to add an extra day to the month of February every four years. Caesar’s math of 365.25 days was close, but it wasn’t the exact 365.242190 days the solar year contains. To be precise, Caesar “overestimated the solar year by 11 minutes,”. This meant the Julian calendar would be short a day every 128 years, according to National
Geographic.
By the 16th century, time had shifted again and not in a good way. Major dates had changed, including Easter. The holiday is supposed to occur on the first Sunday following the first full moon on or after the spring equinox. At the time, Easter’s date had moved by about 10 days. To fix this, Pope Gregory XIII introduced the Gregorian calendar, which kept a leap day every four years but eliminated it during centurial years not divisible by 400. Despite its accuracy, the Gregorian calendar is not flawless. Instead of being off by one day every 128 years like the Julian calendar, it falls short once every 3,030 years. What to do with that extra day every 4 years? Enjoy it!